Tunnel kiln with steam-generating cooling zone



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. DRESSLER Filed Nov. 14, 1919 OOOOO V60i/w' w I .l l I Mw @MM/@ TUNNELKILN WITH STEAM GENERATING COOLING ZONE Aug# 5 p 92@ subject of the KingPatented ug. 5, 1924.

CONRAD DRESSLER, OF NEW YORK, N. Y., KILNS, INC., OF NEW YORK, N.

.ASSIGN OR 4'1.0 AMERICAN DRESSLER TUNNEL Y., A CORPORATION OF NEW YORK.

TUNNEL KILN WITH STEAM -G-ENERATING COOLING- ZONE.

Application led November 14, 1919. Serial No. 338,009.

To all whom t may concern.'

Be it known that I, CONRAD DREssLER, a

of Great Britain, resident of New York, York and State of New York, haveinvented certain new and useful Improvements in Tunnel Kilns withSteam-Generating Cooling Zones', of which the following is aspecification.

My present invention has reference to tunnel kilns or ovens and likestructures, hereafter referred to generally as kilns. In a kiln of thistype goods which may be articles or materials of various kinds areheated for various purposes while passing through a heating zone of thekilns, and are afterward cooled while passing through a cooling zoneof-the kilns which may be a portion of the same kiln chamber as thatincluding the heating zone or may be a separate chamber from the heatingzone.

The object of the invention is to provide a kiln of the characterreferred to with simple and effective means whereby the heat abstractedin the cooling zone from the goods treated and the trucks or other goodscarriers may be utilized for generating steam available for power orother purposes. For this purpose I rovide the cooling zone of the kilnwith suitably disposed pipes or conduits through which water is causedto circulate in such manner and with such speed that the water will beheated to the temperature of steam at a pressure suitable for power andother purposes and provide in conjunction with these pipes, the otherelements, ordinarily including a steam and water drum necessar to form asteam generating boiler of wiich the pipes in the cooling zone of thekiln form the water heating section. The invention is of especialutility where the goods are of a kind permitting them. to be rapidlycooled without injury after being heated to a high temperature.

The various features of novelty which characterize my invention arepointed out with particularity in the claims annexed to and forming aart of this specification. For a' better un erstanding of the invention,however, and the advantages possessed by it reference should be hadtothe accompanying drawings and descriptive matter 1n which I haveillustrated and described a preferred embodiment ofthe invention.

in the county of New Of the drawings:

Fig. l is a somewhat diagrammatic longitudinal sectional elevation;

Fig. 2 is an elevation in section taken similarly to Fig. 1, but on alarger scale and showing a portion only of the apparatus shown in Fig.1'

Fig. 3 is a transverse section taken on the line 3*?) of Fig. l; and,

Fig. 4 is a sectional plan of the portion of the apparatus shown in Fig.2.

In the drawings I have illustrated the use of my invention in a kiln ofthe well-known Dressler type as shown for example by my prior Patents1,023,628 and 1,170,428 but having certain special constructive featuresarising from the use therein of the present invention and'also arisingfrom the fact that the particular kiln, shown by way of example, isintended for use in the fractional distillation of coal. The specialfeatures of kiln construction adapting the kiln for use in distillingcoal form no part vof my present invention but are disclosed in detailand claimed in my co-pending application, Serial No. 338,008 filed ofeven date herewith. This particular form of kiln is one in which thetemperature conditions are such as to make the steam generating featuresof especial value, though they can be utilized to advantage with kilnsemployed for many other purposes.

As shown, the {iln comprises a kiln chamber A enclosed by a refractorymasonry wall B, the latter being usually insulated with kieselguhr orthe like. The kiln is formed with the usual benches C throughout theheating up and high temperature zone of the kiln, these benches beinglocated at opposite sides of the pathway for the goods to be treatedwhich in case of the particular kiln illustrated is coal. On the benchesC are mounted the combustion chambers H which may be formed of the usualhollow walled sections commonly employed in Dressler kilns. The goods tobe treated are carried through the kiln on trucks D or other carriers,the trucks entering the kiln at the inlet end past double doors 'E andleaving the kiln at the opposite end past double doors F This doubledoorarrangement permits of the proper insertion and removal of truckswithout any appreciable entrance of air to, or escape of asesfrom thekiln. Means which may be Offany usual c each valved outlet'Bz throughkiln through the conduit J to ying above the pathway., for the goods. 5o

` slight y inclined p are connected to a header K3 Vbranches 'extendingor suitable typeare provided for introducing fuel and' air .for itscombustion into combustion chamber. The means shown` for this purposecomprise a gas supply nozzle HB and an air supply port HA at one end ofeach combustion chamber. The two ports HA receive air from an air supplyconduit. The products of combustion leave each combustionchamber properat its end remote from that at which air and as are supplied asaforesaid, and pass into Ieat radiating pipes I through which theproducts of combustion pass to an outlet conduitJ.--The vpipes l arelocated on. the benches C and extend along the heating up zone of thekiln, v

Advantageously in some cases means may be employed, as shown, to utilizethe heat in the products of combustion leaving the reheat the airsupplied to the combustion c ambersH by the conduit HA. As shown, theconduit J is connected by a conduit J', and the conduit HA by a conduitHAZ to a recuperator R and the latter is provided with an air inlet R',and a 'stack outlet R2 for products of combustion.

For its special use in distilling coal, the' kiln is provided with a gasl'space above the pathway for the goods and goods carrier whichis ofconsiderable volumetric capacity, and isdivided into a series of o enended compartments by part'tions B which extend across the kiln chamberat intervals 'above' the pathway for the goods.l Each of thesecompartments isl provided with a separate which a. regulated escape ofgas collecting -in the compartment may be provided, lall as is morefully described in my co-pending application re ferred to above.

The goods and goods carrier cooling and steam generating .apparatuswhich is the characteristic feature of the invention claimed hereincomprises, in thepreferred construction illustrated, a series of watertubes K at each side ofthe Pathway for "the oods, and anothergroupowater tubesdxl2 vanta eouslyas shown these tubes are to the horizontal,rising from their ends remote from the ends of the combustion chambers.The tubes K and K2 which is horseits legs ordepending down at the sidesof the pathway for the' goods and connected to the tubes K,while thetubes K2 are connected to the body or yoke ortion of the header. Theopposite ends o the tubes K and' K2 are connected to a similar header K.Water is su plied to the header K4' by a supply pipe M shown as thedelivery pipe o a oiler feed pump M which may bey of usual type. Fromthe top of the drum or header shoe shaped with K3 leads .a dischargepipe 0 which is con.

nected to'a horizontally disposed steam and waterdrum N shown asmountedabove the kiln. As shown the pipe O is connected to the steam andwater drum N by a connection O opening into the drum below the waterlevel therein and by another branch O2 openinginto the top of the steamand water drum. The steam and water drum N 1s'provided with an outlet Pfor steam and with a safety valve Q. To prevent the header K3fromabsorbing heat too rapidly from, and thereby unduly cooling, theadjacent ends of the combustion chambers H, I insert heavy masonry wallsB3 between the ends of the combustion chambers and the correspondingportions of the header K3 and provide flat arches Bt over the pathwayfor the goods above vthese walls B3. These flatl arches may beadvantageously separatedA byl air pockets as shown in Fig. 2. rl`he sidewalls B3 and the arch B4 are shaped t0 fit above the-loaded goodscarrying cars with only the necessary clearance. The constriction in thekiln chamber thus formed minimizes circulation of the kiln atmosphere bywhich the cooling zone might tend to cool the high temperature zone ofthe kiln. The width of the kiln chamber will ordinarily, as shown .inthe drawings, be substantially less in the cooling zone section ofthekiln .than in the heating up section.- i

In operation, the loaded goods carrying trucks D are periodicallyinserted into the kiln one at atime past the doors E and as' each car isthusinserted the train of cars filling the kiln chamber is moved forwarda carlength, a car being removed from they cooling zone of the kiln eachtimea car is inserte the doors E. As a car (past thel doors F in thekiln past gradually perature,

the goods and cars are cooled lby the steam" generating u nit makes itpossible to cool the goods and cars to a temperature at'which they maybe discharged from the kiln' without injury and without an undesirablelossof sensible heat with a length of cooling zone substantiallyshorterthan is necessary with the cooling arran ements heretoforeordinarily employed in ilns of this character. The shortening in the lenkiln structure thus made ossi le materially reduces the cost of kiconstruction and` l uw.

vslowly-moves from ,the doors E to the walls B3 it is slowly and llO hof the Y iosgeo and reduces the ground space required for the kiln,which is a matter of much practical importance in some cases.

The particular construction and arrangement of the steam generating unitis one which is well adapted for efficient and successful operation inthe manner disclosed. lAs the water moves through the tubes K and K2from the header K4 to the header K3, the water-is gradually heated up toa temperature corresponding to the steam pressure desired. The provisionof the steam and water drum well above the tubes and connected to theAheaderl K3 as shown, reduces water hammer and other troubles which mightresultfrom the conversion of considerable quantities of water into steamin the tubes K and K2 and the header K3. The use of means such as arecuperator R for utilizing the sensible heat in the products ofcombustion to preheat the air required for combustion makes it possibleto obtain the economy in fuel resulting from a proper preheating of theair supplied for combustion.

without drawing this air through the cooling-oli' zone of the kiln ashas heretofore been the practice.

While in accordance with the provisions of the statutes I haveillustrated and de scribed the best form of embodiment in my inventionnow known to me, it will be apparent to those skilled in the art thatchan es may be made in the 'form of apparatus isclosed without departingfrom l'the spirit of my invention as set Vforth in the appended claimsand that in some cases certain features of my invention may be used toadvantage without a corresponding use of other` features.

Having now described my invention, what I claim as new and desire tosecured by Letters Patent, is:

1. In a tunnel kiln in which the 'kiln chamber comprises a heating zoneand a cooling zone successively traversed by the goods passing throughthe kiln, the improvement which consists in a steam generating unitcomprising water heating elements located in the kiln chamber inposition to abstract heat from the goods as the latter pass through saidcooling zone.

2. In a tunnel kiln comprising a heating zone and a cooling zone and apathway through the kiln for goods, the improvement which consists inhorizontally disposed water tubes located in the cooling zone portion otthe kiln at the sides and above said pathway, and elements cooperatingwith said tubes to form a steam generating unit.

3. In a tunnel kiln comprising a heating zone and a cooling zone with apathway through the kiln for goods, the improvement which consists in asteam generating unit comprising headers at each end of the cooling zonewhich extend over and having leg portions projecting down at the sidesot the pathway, tubes connecting said headers, a steam and water drumexternal of the kiln to which the header at the hot end of the coolingzone is connected 'and means for forcing feed water into the header atthe other end. i

4. In a tunnel kiln comprising a heating zone and a cooling zone with apathway through the kiln for goods, the improvement which consists in asteam generating unit comprising water heating elements located in saidcooling zone in position to abstract heat from the goods passing throughsaid zone, and a barrier .at thejunction between the heating and'cooling zones closely encircling said pathway to minimize a circulationof kiln the heating and cooling. zones.

5. In a tunnel kiln comprising a heating zone and a cooling zone with apathway through the kiln for goods, the improvement which consists in asteam generating unit comprising water heating elements located in saidcooling zone in position to abstract heat from the goods passing throughsaid zone, and a barrier at the junction between the heating and coolingzones closely encircling said pathway to minimize a circulation of kilnatmosphere between the heating and cooling zones, the portion of saidbarrier above the pathway being formed of flat arches separated from oneanother by air Spaces extending transversely to the pathway.

6. In a tunnel kiln comprising a heating zone and a cooling zone with apathway through the kiln for goods, and combustion chambers located inthe heating zone and fuel supply means and air inlets for the combustionchambers, the improvement which consists in a steam generating unitcomprising water heating tubes located in the cooling zone and incombination therewith means for utilizing the hot products of combustionleaving the combustion chambers for preheating the air supplied to theair inlets of said combustion chambers. l

Signed at New York, in the county of New York and State of New York,this thirteenth day of November A. D. 1919.

CONRAD DRESSLER.

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